Where did the snakes on earth come from? The World Serpent - religious secrets of various peoples of the world
The slender-tailed snake is a non-venomous snake, although like all its fellows it is a predator. It feeds on small rodents, birds, and reptiles. In general, this is the lifestyle of most snakes. You have to use your torso, which is very strong. Since it has no paws, and its mouth is not very large. If the runner applies all its force to a metal point, it can break the metal rod out of the fence. This is due to the fact that the muscles run along the spine, and unlike a person, she can immediately contract or relax all the muscles.
Slender-tailed snake
Snakes are quite ancient creatures. They live on our planet from 180 to 250 million years. That is, in fact, they are the same age as dinosaurs. Snakes appeared in the Triassic period. From there the very first remains of these creatures are known. This group of reptiles has survived to this day in part due to the fact that most snakes lead a secretive lifestyle.
Why did they lose their limbs? There were a lot of different reptiles on Earth back then. Then many predators appeared. And it was necessary to hide somehow. And apparently, the ancestors of snakes switched to living in the soil. With a burrowing lifestyle, oddly enough, the paws often get in the way. And in the end, the ancient snakes decided to part with them. The process of loss of limbs was gradual, first the forelimbs were lost. Then only the hind limbs remained. Already the snake of the Jurassic period had only hind limbs. These hind limbs have shrunk so much that they look like two claws located at the base of the tail. The snake finally lost its legs about 80 million years ago.
But who was their ancestor? This is a much more complicated question. The fact is that in their structure, both external and internal, snakes are very similar to lizards. Among lizards there are forms without legs. The well-known spindle. Accordingly, it is logical to assume that the ancestors of snakes were lizards. And so scientists who studied the structure, as well as the molecular relationship of groups of lizards, settled on two options.
Varan
These are monitor lizards. He has a tongue similar to a snake’s, and the structure of the skull is similar to a snake’s; these are movable lower jaws. Both halves of the lower jaw are not tightly connected. They don't have a chin, they just have cartilage tissue. In such cases, the jaw may move to the side and allow large food to pass through. And scientists concluded that some representatives of the monitor lizards lost their limbs. It is possible that some monitor lizards “decided” to go underground altogether, then lost their limbs, and this is how snakes appeared.
Other zoologists disagree with this point of view. Partly because among monitor lizards, both extinct and modern, there have never been legless forms. That is, they had no tendency to lose limbs. Moreover, many monitor lizards lead a soil lifestyle, but nevertheless they do not lose their paws. The spine structure of a snake and a monitor lizard are different. And here the similarity should be much more pronounced. Therefore, among the candidates for the role of the snake’s ancestor, monitor lizards come in last place.
And who do scientists put in first place?
![](https://i1.wp.com/mirznayki.ru/wp-content/uploads/2019/04/jcs-gekko-gecko.jpg)
Gecko currents.
Gekos are usually nocturnal. It would seem that there is no resemblance to snakes. The fact is that geckos can form legless forms. New Guinea and Australia are home to interesting soil hickons called lepidoptera. Which have no forelimbs, and what remains of the hind limbs are two small sticks, extremely similar to those of the Mesozoic ancestors. Geckos have an extremely similar skull structure in that neither has temporal or zygomatic arches. The very parts that support the eye. Therefore, the eye lies in the fossa, without any restrictions. In addition, both geckos and snakes have the same structure of the spine. And more recently, molecular biologists, having studied the DNA of the geeks, discovered that in reality and even the hereditary substance of the representatives of these two groups are extremely similar. So, most likely snakes originated from geckos.
Spawns four totems that each provide a stacking buff, much like the old brawl against Mingus Copps , which was introduced in Mists of Pandaria. Kite and rotate Ancient Serpent to the different totems to avoid the buffs getting too powerful and clear stacks from the other titems. Aim at avoiding the healing and defensive totem as much as possible; or pick a combination that suits your playstyle. The red totem is damage, the green is healing, the white is defense, and the blue is haste.
Comment from Fatwall
If you cycle between just two of the totems, the buffs they apply to the boss won"t drop off.If you want the buffs to reset, you"ll likely need to at least juggle three different buffs on the boss.
Comment from BlueInferno
This boss also uses the Toxic Clash ability, so keep on the move or else he will one-shot youAs soon as he spawns, position him by the totem immediately to your left (haste buff). Burst him down and bring him to the top left totem (defensive) when he reaches anywhere between 10-13 haste buff stacks. Keep him at the defensive totem until he is clear of the haste buff (~35 s) and them back to the haste totem. Rinse and repeat.
It may be a dps check for some, depending on gear level, so be sure to take
Many people believe that snakes reproduce solely by laying eggs. There is some truth in this belief; most creeping creatures reproduce this way. However, there are also viviparous reptiles. How do snakes give birth? We will try to answer this question in this article.
How does conception occur?
Before snakes give birth to their offspring, conception occurs in one way or another. Reptiles are divided into females and males, which are endowed with the corresponding genital organs. During conception, the snakes' tails touch while the male inserts his sexual organ into the female's cloaca. After this, after some time, most creeping creatures lay eggs. However, viviparity or ovoviviparity also occurs. What is it?
Reproduction by ovoviviparity
This unpronounceable word was coined by zoologists who observed snakes giving birth. With this type of reproduction, the female keeps the eggs within herself until the babies hatch from them. The mother's circulatory system penetrates the egg, thanks to which the fetus is nourished until birth.
All boas, asps, and some species of vipers are ovoviviparous. This method of procreation is very convenient for snakes, since the female can hunt and defend herself at this time. Reptiles that lay eggs in a nest are deprived of this opportunity. For example, the king cobra is forced to tirelessly stay near the eggs until the offspring are born.
The development of ovoviviparity and viviparity began in northern latitudes, since the snake is a cold-blooded animal and does not have the ability to warm the eggs with the heat of its body. When babies develop in the womb, they automatically have the mother’s body temperature, which makes it possible to develop normally even in unfavorable weather conditions.
Viviparous snakes
The evolutionary level of certain reptiles has reached the point that some of them are viviparous, that is, they do not form eggs. With this type of reproduction, a placenta is formed in the snake, through which nutrients are supplied to the cubs. Otherwise, the process is no different from the birth of young in mammals.
Thanks to many years of observations by scientists of reptiles, we now know how a snake gives birth? Vipers, snakes and some species of sea snakes hatch their offspring without laying eggs.
Breeding frequency
The snake reproduces annually, but the number of copulations directly depends on the climate of the cold-blooded habitat. On average, the number of copulations, and therefore births, is no more than twice a year. The female is capable of giving birth to from one to 100 viable young. After birth they are completely independent.
The gestation period in females lasts from two to five months, depending on the type of reptile. However, this is quite difficult to determine, since the snake is able to retain live sperm inside itself for several years after copulation.
Traditional egg laying
Not long ago, scientists estimated that only about 70% of snakes lay eggs. All other species are viviparous or ovoviviparous. Egg laying occurs after copulation, which occurs in the same way in all reptiles. After fertilization, eggs are formed in the female’s body, and after a while she lays them in the nest. Until the offspring appear, the snake sits motionless near them, protecting the cubs from potential enemies. In this state, the female is hungry and very aggressive. Any encounter with a snake hatching babies can end in disaster.
Before giving birth, snakes carefully select a place to form a nest. Piles of rotting organic debris are ideal for these purposes, as they can protect future hatchlings from the elements. The incubation period for eggs varies from one to several months, depending on the variety of cold-blooded fish.
Lifespan of a snake
After the snake has given birth to cubs, they begin to actively develop and reach sexual maturity. Depending on the type of cold-blooded animal, this period occurs in the second, third or fourth year of life. By this moment, the growth of the reptile also reaches its maximum.
The lifespan of creeping creatures varies from 20 to 30 years, but it is quite rare to find long-livers among them. The majority do not live to old age due to premature death from attacks by birds of prey and unfavorable environmental conditions.
How snakes are born directly depends on the type of reptile. All types of reproduction described above take place.
We already know what the first people looked like on Earth. Now scientists have revealed what the first snakes looked like.
The ancestors of all modern snakes had tiny hind limbs with full ankles and toes. They were predators and ambushes at night... The first snakes are described in the journal BMC Evolutionary Biology.
The research was carried out by an international team of scientists. Scientists analyzed the fossil remains, genes and anatomical structure of 73 species of snakes and lizards. Biologists have concluded that the first snakes appeared on land apparently in the warm forests of the southern hemisphere 128 million years ago (Early Cretaceous).
At the dawn of their evolution, snakes hunted soft-bodied animals that were significantly larger than them. But snakes did not yet know how to strangle prey with their coils. Next to the remains of extinct snakes (as found in 1987), fossilized remains of shells are found - this is evidence that snakes ate eggs and baby dinosaurs.
The first snakes were active at night. But in the Cenozoic (about 45-50 million years ago), ancient snakes began to crawl out to hunt during the day. It is assumed that it was the cold at night that forced the snakes to change their habits. This is how the superfamily of higher snakes appeared - Colubroidea -
to which more than 85% of modern species belong.
The evolutionary success of snakes, according to scientists, lies in their ability to settle over vast territories and establish themselves in areas inhospitable to other land animals.
Snakes - Serpentes - live on all continents except Antarctica and several islands. All known snakes are predators. They are poisonous and non-poisonous. Poisonous ones kill their prey with poison. Non-venomous snakes either swallow their prey whole or first suffocate it.
The largest known snakes living on Earth are the reticulated python and the anaconda water boa. The length of the smallest living snakes - Leptotyphlops carlae - does not exceed 10 centimeters.
Snakes are mainly terrestrial, but some species live underground, in water, and in trees. When unfavorable conditions occur (for example, when it gets cold), snakes hibernate.
Most snakes reproduce by laying eggs, but some species are viviparous.
Where did snakes come from?
Snakes have demonstrated miracles of adaptation and evolutionary success since the time when dinosaurs disappeared from the face of the Earth. But where did they come from? How did a four-legged reptile turn into a snake? Where are the transitional forms confirming such an evolution?
In fact, losing your legs is the simplest part of the transformation. This happened to many groups of four-legged animals, and they all evolved independently. Legless reptiles include not only snakes, but also a group of extant amphisbaenians, as well as some lizards, including individual skinks, Australian lepidoptera, spindles and yellowbellies. Among amphibians, legless ones stand out ( Apoda), which developed worm-like bodies, as well as sirens, which retained shortened forelimbs and lost their hind limbs. In addition, at least two extinct groups of amphibians, the storopods and lysorophids, also became legless. Almost all of these animals burrowed into the ground, so without limbs it was obviously easier for them to make their way through the soil or soft silt. There's a simple reason why it's easy to lose limbs. The development of the limb buds and the paws themselves is controlled by a certain set of Hox genes and Tbx genes: as soon as they stop giving the command to grow limbs, they disappear.
However, it seems unlikely to find a fossil snake that was in the process of losing its limbs. In general, snakes do not fossilize well because their bodies are made up of hundreds of thin vertebrae and ribs, which break down and dismember. Single specimens are known from partially preserved or complete skeletons. Most fossil snakes are found from several vertebrae, and the appearance of the animal is based on scanty data on the shape of the spine.
Despite these obstacles, the fossil record contains many remarkable fossils that trace the transition from four-legged lizards to legless snakes. At the first stage we find many fragmentary fossils from the Jurassic period. Followed by Adriosaurus microbrachis- a fossil animal found in 2007 in mid-Cretaceous rocks (age - about 95 million years) in Slovenia (Fig. 13.3, A). This name translates as "Adriatic lizard with small front legs." Adriosaurus was a very slender, long sea lizard with fully functional front legs, but non-functional vestigial hind legs.
Rice. 13.3. Intermediate fossil adriosaur: this animal had tiny front legs, but full-sized hind legs :( A) skeleton; ( B) reconstruction of the external appearance (illustrations courtesy of M. W. Caldwell)
Then we meet a variety of snakes that no longer have front limbs, but still have tiny, non-functional hind limbs. For example, Najash rionegrina was an earthen land snake; it was described in 2006 from fossils about 90 million years old found in the Candeleros Formation in Argentina (Nahash is the ancient biblical name for the serpent that lived in the Garden of Eden). U Najash the pelvic girdle was preserved - the vertebrae articulated with the sacrum, as well as rudimentary hind limbs, which contained femurs and tibias.
Even more specialized and snake-like are the extraordinary reptile fossils found in Late Cretaceous marine rocks in Israel and Lebanon. Of these fossils, the best preserved Haasiophis terrasanctus(Fig. 13.4). The name of this animal - Haas's Snake of the Holy Land - was given in honor of the Austrian paleontologist Georg Haas, who discovered its location and managed to describe the fossil before his death in 1981. Haasiofis was found in limestone near the town of Ein Yabrud in the Judean Mountains, near the city of Ramallah on the West Bank. The age of the fossil is 94 million years. It is an almost complete skeleton (88 cm in length), missing only the tip of the tail. The skull and most of the vertebrae look similar to those of most other primitive snakes. However, the hind limbs were also present here - very small, but with a femur, both tibias and part of the foot. Unlike the hind limbs Najash, pelvic bones Haasophis very small and no longer connected to the spine; they are completely rudimentary and useless. Haasophis and many other snakes of the Cretaceous period apparently had a vertical fin and a paddle-shaped tail, like modern sea snakes.
Rice. 13.4. Two-legged snake haasiophis: ( A) a fully articulated skeleton with preserved rudimentary hind limbs (large dark blocks - cork inserts, thanks to which nothing can be placed on the sample); ( B) fragment of vestigial hind limbs (illustrations courtesy of M. Polcyn, Southern Methodist University)
The slightly larger snake from Ein Yabrud is called Pachirahis; Haas described it in 1979. Although the fossil record is more fragmentary than that of Haasiophis, the meter-long body also bears tiny, vestigial hind limbs. The ribs and vertebrae of Pachyrahis are very thick and dense, which probably helped it swim at great depths in the Cretaceous seas.
Third snake from marine Near Eastern limestones - Eupodophis descouensi, found in Lebanon (near Ein Yabrud) in rocks about 92 million years old (Fig. 13.5). The generic name of this animal means “a real snake with legs,” and the specific name is given in honor of the French paleontologist Didier Decoin. This creature was 85 cm long, about the same as Haasiophis, but its limbs were even more reduced than those of the bipedal snakes of the Cretaceous period: Haasiophis and Pachyrahis.
Rice. 13.5. Two-legged snake Eupodophis: ( A) complete skeleton with preserved vestigial hind limbs; ( B) fragment of the spine, which also shows vestigial hind limbs (illustrations courtesy of M. W. Caldwell)
Thus, not only the vestigial hind limbs of several extinct Late Cretaceous sea snakes, but also the vestigial pelvic and femur bones (sometimes with tiny "twigs" extending from them) of primitive living snakes, particularly boa constrictors and their relatives, provide silent but convincing evidence the origin of snakes from four-legged creatures.
But what is the common ancestor of all snakes? The first ideas about this were expressed by one of the pioneers of paleontology and herpetology, Edward Drinker Cope, who noticed that anatomically snakes are in many ways similar to monitor lizards, for example, Australian and Komodo monitors (especially with mosasaurs - sea lizards of the Cretaceous period). Anatomical facts also seem to support the relationship of snakes with monitor lizards, but the latest data from molecular biology do not; they are ambiguous. Some molecular sequences allow us to consider snakes as the closest relatives of monitor lizards, while others do not allow us to consider them relatives of any of the existing families of lizards.
The view that snakes lost limbs as they migrated to the sea is probably supported by many fossils of sea snakes from the Cretaceous rocks of the eastern Mediterranean (Slovenia, Israel, Lebanon). According to this version, the loss of the ears and the appearance of solid transparent snake eyelids may be due to adaptation to swimming, and not to a burrowing lifestyle.
Another school of zoology develops the idea that snakes could have evolved from land lizards rather than from swimming lizards, such as the Kalimantan earless monitor lizard. Proponents of this idea believe that the transparent eyelids were supposed to protect the snake's eyes from coarse coarse sand when buried in the ground, and the auricle could disappear because without it, less dirt gets into the ear cavity. "Land" adaptation traits Najash are consistent with this point of view, although he lived somewhat later than the sea snakes Haasiophis, Pachyrahis and Eupodophis. The most primitive of all known snakes is Coniophys, which had a lizard-like head and a snake-like body. True, its fossil is too poorly preserved to be used to judge the animal’s limbs. However, it was land, not sea. The water lizard Adriosaurus is an even more primitive relative of snakes. She had four legs and swam in the ocean.
Accordingly, the secret of the closest relatives of snakes has not yet been revealed. This is exactly how science develops: contradictions like the above are very important for the scientific process, only in this way can we carefully study all the facts and not discard existing versions. Regardless of how the debate is ultimately resolved, the fact is that many fossils exhibit features that illustrate the transition from quadrupedalism to bipedalism to leglessness. This confirms that snakes evolved from four-legged ancestors.